Tool wear mechanisms for milling in situ TiB₂ particle-reinforced Al matrix composites

In situ TiB₂ particle-reinforced Al matrix composite is a new kind of metal matrix composite (MMC). With in situ synthesis method, a better adhesion at interfaces is achieved and hence improves mechanical properties. Due to the presence of hard ceramic particles, the tool wear is seriously compared with traditional metal while cutting in situ TiB₂/Al MMC. Many studies have been carried out on tool wear and wear mechanisms for cutting ex situ SiC/Al MMCs. However, few papers about the tool wear for cutting in situ particle-reinforced Al matrix composites have been published. In this paper, tool wear, tool life, and wear mechanisms for milling in situ TiB₂/Al by using uncoated carbide tools were investigated. The results show that the tools were worn out at the initial tool wear stage, which indicated that the wear of tool was rapid. Among all the cutting parameters, milling speed has dominated influence on tool life, followed by feed rate and cutting depth. During milling in situ TiB₂/Al MMC, the uncoated tools suffered from abrasive and adhesive wear, chipping and peeling wear, microcracks, and diffusion and oxidation wear.